The present invention relates to a helicopter rotor, in particular, one on which the hub is essentially designed in the form of a flat plate with radial arms, the free ends of which are connected to one another by perimetrical bridge elements, each for connecting a blade to the hub.
On known rotors of the above type, the connection is generally made using a fork element extending round the bridge element and arranged radially with its open end facing outward to receive the connecting end of the blade. Between each fork element and the bridge element, an elastomeric bearing is usually employed for relieving the centrifugal shearing forces transmitted by the blade to the bridge element and, consequently, to the hub. The forces in the hub plane caused by drag, on the other hand, are relieved by dampers essentially arranged in the hub plane itself, between a point on each blade and a point on the hub rim away from the blade connecting point.
A major drawback of known rotors of the above type is the presence of the dampers, operation of which is usually limited to relatively short periods but the presence of which results in a considerable increase in the weight of the rotor, and makes dynamic balancing extremely difficult and is a frequent cause of breakage.